The trophodynamics of Southern Ocean Electrona (Myctophidae) in the Scotia Sea
The trophodynamics of Southern Ocean Electrona (Myctophidae) in the Scotia Sea
复制标题
斯科舍海南大洋电子鱼（Myctophidae）的营养动力学
作者：
R. Saunders;M. Collins;Emma Foster;R. Shreeve;G. Stowasser;P. Ward;G. Tarling
斯科舍海是南大洋产量最高的区域之一，但其表层水域的温度正在迅速上升，这可能正在改变许多真菌类昆虫及其猎物物种的行为和分布。南极洲电子线虫和卡尔斯伯吉电子线虫是该地区最丰富的两种真菌类昆虫，但人们对它们的生态了解很少，很难确定它们对正在进行的环境变化的反应。这项研究利用春季、夏季和秋季在斯科舍海部署的中水拖网，调查了它们的丰度、种群结构和食性的时空模式。南极是数量最多的物种(0.09-0.21个)。1,000立方米−3)，最集中在海冰部分。Carlsbergi发生在更北部的地区，密度为0.02-0.11个。1,000m−3.有证据表明两个物种的深度分布、与大小相关的性别二型性和特定于大小的垂直分层存在季节性变化。在南极东部，性别比和雌性体型的纬度趋势是明显的。它的食物因地区、季节和大小等级的不同而不同，但总体而言，它是Euphausia Superba、Metridia spp.和Themisto gaudichaudii是优势猎物。E.Carlsbergi似乎没有在斯科舍海招募人员。它的食物以桡足类为主，特别是长菊头蝠和Metridia spp.，但区域、季节和个体发育差异明显。这项研究有助于我们理解南大洋中水食物网的结构及其对持续环境变化的敏感性。
The Scotia Sea is one of the most productive regions of the Southern Ocean, but its surface waters are experiencing a rapid increase in temperature, which may be changing the behaviour and distribution of many myctophids and their prey species. Electrona antarctica and Electrona carlsbergi are two of the most abundant myctophids in the region, but their ecology is poorly understood and their response to ongoing environmental change is difficult to determine. This study investigated spatial and temporal patterns in their abundance, population structure and diets using mid-water trawl nets deployed across the Scotia Sea during spring, summer and autumn. E. antarctica was the most numerically abundant species (0.09–0.21 ind. 1,000 m−3), with greatest concentrations occurring in the sea-ice sectors. E. carlsbergi occurred in more northern regions, comprising densities of 0.02–0.11 ind. 1,000 m−3. There was evidence of seasonal variation in depth distribution, size-related sexual dimorphism and size-specific vertical stratification for both species. Latitudinal trends in sex ratio and female body size were apparent for E. antarctica. Its diet varied between regions, seasons and size classes, but overall, Euphausia superba, Metridia spp. and Themisto gaudichaudii were the dominant prey items. E. carlsbergi appeared not to recruit in the Scotia Sea. Its diet was dominated by copepods, particularly Rhincalanus gigas and Metridia spp., but regional, seasonal and ontogenetic variations were evident. This study contributes to our understanding of how mid-water food webs are structured in the Southern Ocean and their sensitivity to ongoing environmental change.